/Engine/Source/Developer/CollectionManager/Public/ICollectionManager.h
Event for when assets are added to a collection
typedef TMulticastDelegate_TwoParams< void, const [FCollectionNameType](API\Developer\CollectionManager\FCollectionNameType) &, TConstArrayView< [FSoftObjectPath](API\Runtime\CoreUObject\UObject\FSoftObjectPath) > > FOnAssetsAddedToCollection